Circulating factors that modify lung cell DNA synthesis following exposure to inhaled oxidants. II. Effect of serum and lavage on lung pneumocytes following exposure of adult rats to 1 ppm ozone.
Adult rats were exposed to 1 ppm (1.96 mg/m3) ozone or air for 2 wk. Animals were sacrificed at 3, 5, 7, or 14 d after the onset of exposure, and samples of plasma and lung lavage were obtained. Heat-inactivated plasma and lavage from animals exposed to ozone for 5 or 7 d significantly increased DNA synthesis by lung pneumocytes compared with plasma or lavage from air-exposed animals. Fractionation of plasma and lavage samples indicated that the factor responsible had an isoelectric point of 6.45-6.75, and a molecular weight of 38 +/- 3 kDa. This factor has a dose-dependent effect on lung pneumocyte DNA synthesis in culture. It has no effect on cultured fibroblast DNA synthesis, and is distinct from a previously described factor in the plasma of these ozone-exposed animals that enhances fibroblast DNA synthesis. The factor is detectable within 5 d of exposure, and may hold some promise as a marker of early oxidant lung injury.
Tanswell
A K
AK
Department of Pediatrics and Anatomy, University of Western Ontario, London, Canada.
Fraher
L J
LJ
Grose
E C
EC
D000280:Administration, Inhalation; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000096:biosynthesis* / Q000378:metabolism; D007525:Isoelectric Focusing; D008168:Lung / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D010126:Ozone / Q000008:administration & dosage / Q000633:toxicity*; D051381:Rats; D013997:Time Factors
D010126:Ozone; D004247:DNA